The company (Uber, Instacart, etc) is basically:

1. An app for drivers/shoppers.
2. An app for consumers.
3. The servers to facilitate communication.
4. A subcontracted call center in India for support and customer service.
5. A third-party payroll processor.
6. A handful of administrative people and techs to keep it running. Plus some shareholders to take the money.

So not counting drivers and contracted services, it's practically a small business. Seems easy enough to emulate.